A spokesperson for the assembly said it was aware that “two flags were flown without permission from the roof” and it was investigating.

DUP assembly member Peter Weir said he had been assured by the assembly that “these were rogue actions and are being fully investigated”.

“The point is if you have a situation where these sizeable flags can be put on top of Stormont’s roof what is to stop someone bringing on a banner another day? There are serious issues here.”

SDLP Assembly Member John Dallat MLA has called on other members to retain a sense of perspective.

“The arrangements for flying flags at the Assembly should, of course, be upheld. But there are much more important matters to tackle than if an Irish tricolour flies over the Northern Ireland Assembly,” he said.